1. Field of the Invention
The present invention relates to a wheeled moving robot.
2. Description of the Related Art
A wheeled moving robot which drives wheels and moves freely in an operational environment may not be able to start to move from a still state when there are bumps on the floor surface and/or the static friction force between the wheels and the floor surface is large.
In fact, the static friction force between the wheels and the floor surface changes considerably in relation to the materials of the wheel rims and the materials of the floor surface. In order that the robot can move regardless of the materials, the robot must have a large sized actuator which generates large torque at a movement start and therefore has high electricity power consumption. However, since the wheeled moving robot is mainly driven by a battery, a small sized robot which has low electricity power consumption is desirable.
Moreover, as a method of compensating the static friction force of the actuator, there is proposed a method that compensates the static friction of a shaft at a rotation start by adding dither compensation torque instructions to the actuator so as to prevent a delay of the rotation start. (See, Japanese patent application (KOKAI) 8-286759) However, this method merely enhances a response performance of the actuator at the rotation start of the shaft insofar as the actuator can generate sufficient torque which exceeds the static friction force, such as with an industrial robot. However, the proposed method can not rotate the shaft when the torque generated by the actuator can not exceed the static friction force.